In wake of Attorney General Jeff Sessions' repeal of Obama era guidance on legal marijuana, Denver Mayor Michael Hancock is more worried about the marijuana business than he is about a law enforcement crackdown on weed.

"When we see an industry, that is dependent upon investors, people who are putting their hard-earned money into the industry, this sort of move does not help whatsoever," Hancock, a Democrat, said Friday on CNBC's "Closing Bell." "All this move does is demonstrate how out of step the attorney general sessions is and the administration is with the rest of the country."

Sessions, a longtime opponent of marijuana legalization, on Thursday moved to rescind the Cole Memo, a document which de-prioritized the use of federal funds to enforce cannabis prohibition. The memo effectively handed control of marijuana enforcement and regulation to the states, except in certain circumstances.

"We've already had conversations with our attorney general, as well as our acting U.S. attorney, who clearly have said they're not going to change anything with regards to the industry here in Colorado," Hanckock said.

Hancock said Denver reaps about $18 million to $20 million in tax revenue just from recreational marijuana. That money goes toward implementing marijuana regulation, including inspections, law enforcement and public education, all of which Hancock worries might disappear following Sessions' decision.

"Cities also fall into this uncertain category, when you have the attorney general acting as irresponsible as he has acted with regards to the memo," Hancock said.

Investment and taxes aside, the ground-level industry is very cash heavy. Even with the Cole Memo, banks and credit unions operating under federal charters had little incentive to help cannabis businesses, which are still federally illegal, according to a representative from the Colorado Bankers Association.

"What we would hope our attorney general would do to work with Congress, begin the process of working on a pathway to banking for this industry," Hancock said.